Tether

Tether Operations Limited is the issuer of USD₮ (USDT), the largest stablecoin by circulating supply, along with XAU₮ (gold-backed), USA₮ and EUR₮ tokens issued across Ethereum, Tron, TON, Solana, Bitcoin/Liquid, Avalanche, Polygon, Arbitrum, Plasma and other chains. Beyond token issuance, Tether ships a developer surface centred on the open-source Wallet Development Kit (WDK) — a modular, self-custodial multi-chain wallet framework distributed as @tetherto/* npm packages, a WDK CLI, a React Native UI kit, an MCP Toolkit that exposes 35 wallet, pricing, indexer, swap, bridge, lending and fiat tools to AI agents, a published Agent Skill, and the hosted WDK Indexer REST API (wdk-api.tether.io) for token balances and transfer history. Tether also operates the QVAC local-AI SDK, the Tether Wallet app, and a public bug-bounty program.

Tether publishes 5 API contracts indexed on the APIs.io network, including API Keys API, Chains API, Health API, and 2 more. Tagged areas include Company, Stablecoins, Cryptocurrency, Blockchain, and Wallets.

The Tether catalog on APIs.io includes 1 Spectral governance ruleset.

Tether’s developer surface includes documentation, API reference, getting-started guide, support, engineering blog, signup flow, CLI, and 28 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

52.1/100 developing ▬ flat Agent 33/100 agent ready Front door AI 4/6 moderate Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 published contract 1 MCP Servers 3 Agent Skills

Company Stablecoins Cryptocurrency Blockchain Wallets Digital Assets Payments Self-Custody Multi-Chain Agents MCP Open Source Stablecoin Issuance

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 52.1/100 · developing

Contract Quality 7.8 / 19

Developer Ergonomics 12.9 / 15

Access Clarity 5.1 / 15

Operational Transparency 5.9 / 10

Contract Governance 1.6 / 9

Discoverability 5.4 / 8

Regulatory Posture 4.2 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 33/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 4 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Payments regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks

5 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 41.6 — up to +14.6 composite points
Access Clarity scores 34.2 — up to +13.2 composite points
Contract Governance scores 18.2 — up to +9.8 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/tether/apis.yml: open an issue on github.com/api-evangelist/tether to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Agent Skills (SKILL.md packages)	builds-on	26.8 (thin)	-	1
Stablecoins and Tokenization (stablecoin issuers, tokenized assets)	builds-on	26.8 (thin)	-	1
Flathub Linux App Publishers (company-published, domain-verified Linux desktop apps)	builds-on	26.8 (thin)	-	1

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 3

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

Model Context Protocol (MCP)

measured — observed by APIs.io (documented)

Agent Skills

measured — observed by APIs.io (published)

OpenAPI

measured — observed by APIs.io (published)

APIs 5

Individual APIs this provider publishes, each with its own machine-readable definition.

Tether API Keys API

The API Keys API from Tether — 2 operation(s) for api keys.

Tether Chains API

Supported blockchains and token discovery

Tether Health API

Server health and status checks

Tether Token Balances API

Query current token balances for addresses

Tether Token Transfers API

Query token transfer history for addresses

Open Collections 5

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

WDK Indexer API Keys API

OPEN COLLECTION

WDK Indexer Chains API

OPEN COLLECTION

WDK Indexer Health API

OPEN COLLECTION

WDK Indexer Token Balances API

OPEN COLLECTION

WDK Indexer Token Transfers API

OPEN COLLECTION

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Tether MCP Server

Local (stdio) MCP server; 35 tools listed.

MCP SERVER

Agent Skills 3

Packaged agent skills for driving this provider's APIs from an AI assistant.

tether-indexer-api-keys

AGENT SKILL

tether-indexer-balances-and-history

AGENT SKILL

wdk

AGENT SKILL

Rate Limits 1

Documented rate limits and quota policies.

Tether Rate Limits

6 limits

RATE LIMITS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Tether API Rules

48 rules · 46 errors 1 warnings 1 info

SPECTRAL

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Tether Wdk Indexer Overlay

11 actions · servers · tether-wdk-indexer-openapi-original.yml

DERIVED

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Tether Authentication

apiKey · 1 scheme

SECURITY

Tether Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Tether Vulnerability Disclosure

Hackerone · security.txt

SECURITY

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

SignUp

Sandbox

Documentation 3

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

OpenAPI

OpenAPI

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

MCPServer

AgentSkill

WellKnown

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Components

Conventions

ErrorCatalog

DataModel

Lifecycle

Conformance

Build 5

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

Packages

SDKs

CLI

ToolCrosswalk

Access & Security 4

Authentication, authorization, and security posture

Security

Security

Authentication

Authentication

DomainSecurity

DomainSecurity

VulnerabilityDisclosure

VulnerabilityDisclosure

Operate 3

Status, limits, changes, and where to get help

Support

Support

RateLimits

RateLimits

ChangeLog

ChangeLog

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 3

The organization behind the API

BlogRSS

BlogRSS

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: tether
name: Tether
description: Tether Operations Limited is the issuer of USD₮ (USDT), the largest stablecoin by circulating supply, along with
  XAU₮ (gold-backed), USA₮ and EUR₮ tokens issued across Ethereum, Tron, TON, Solana, Bitcoin/Liquid, Avalanche, Polygon,
  Arbitrum, Plasma and other chains. Beyond token issuance, Tether ships a developer surface centred on the open-source Wallet
  Development Kit (WDK) — a modular, self-custodial multi-chain wallet framework distributed as @tetherto/* npm packages,
  a WDK CLI, a React Native UI kit, an MCP Toolkit that exposes 35 wallet, pricing, indexer, swap, bridge, lending and fiat
  tools to AI agents, a published Agent Skill, and the hosted WDK Indexer REST API (wdk-api.tether.io) for token balances
  and transfer history. Tether also operates the QVAC local-AI SDK, the Tether Wallet app, and a public bug-bounty program.
url: https://raw.githubusercontent.com/api-evangelist/tether/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - rate-limits
  - security
  - sandbox
  generated: '2026-11-06'
  method: derived
image: https://tether.io/wp-content/themes/tether-io-theme/assets/images/logo.svg
x-type: company
x-source: harvest:secondary-market
specificationVersion: '0.23'
created: '2026-08-05'
modified: '2026-10-06'
tags:
- Company
- Stablecoins
- Cryptocurrency
- Blockchain
- Wallets
- Digital Assets
- Payments
- Self-Custody
- Multi-Chain
- Agents
- MCP
- Open Source
- Stablecoin Issuance
tags_raw:
- Company
- Stablecoins
- Cryptocurrency
- Blockchain
- Wallets
- Digital Assets
- Payments
- Self-Custody
- Multi-Chain
- Agents
- MCP
- Open Source
- Open-Source
- Stablecoin Issuance
apis:
- aid: tether:tether-api-keys-api
  name: Tether API Keys API
  description: The API Keys API from Tether — 2 operation(s) for api keys.
  humanURL: https://docs.wdk.tether.io/tools/indexer-api
  baseURL: https://wdk-api.tether.io
  tags:
  - APIKeys
  tags_raw:
  - API Keys
  properties:
  - type: OpenAPI
    url: openapi/tether-api-keys-api-openapi.yml
  - type: Documentation
    url: https://docs.wdk.tether.io/tools/indexer-api
  - type: APIReference
    url: https://docs.wdk.tether.io/tools/indexer-api/api-reference
  - type: GettingStarted
    url: https://docs.wdk.tether.io/tools/indexer-api/get-started
  - type: SignUp
    url: https://wdk-api.tether.io/register
- aid: tether:tether-chains-api
  name: Tether Chains API
  description: Supported blockchains and token discovery
  humanURL: https://docs.wdk.tether.io/tools/indexer-api
  baseURL: https://wdk-api.tether.io
  tags:
  - Chains
  properties:
  - type: OpenAPI
    url: openapi/tether-chains-api-openapi.yml
  - type: Documentation
    url: https://docs.wdk.tether.io/tools/indexer-api
  - type: APIReference
    url: https://docs.wdk.tether.io/tools/indexer-api/api-reference
  - type: GettingStarted
    url: https://docs.wdk.tether.io/tools/indexer-api/get-started
  - type: SignUp
    url: https://wdk-api.tether.io/register
- aid: tether:tether-health-api
  name: Tether Health API
  description: Server health and status checks
  humanURL: https://docs.wdk.tether.io/tools/indexer-api
  baseURL: https://wdk-api.tether.io
  tags:
  - Health
  properties:
  - type: OpenAPI
    url: openapi/tether-health-api-openapi.yml
  - type: Documentation
    url: https://docs.wdk.tether.io/tools/indexer-api
  - type: APIReference
    url: https://docs.wdk.tether.io/tools/indexer-api/api-reference
  - type: GettingStarted
    url: https://docs.wdk.tether.io/tools/indexer-api/get-started
  - type: SignUp
    url: https://wdk-api.tether.io/register
- aid: tether:tether-token-balances-api
  name: Tether Token Balances API
  description: Query current token balances for addresses
  humanURL: https://docs.wdk.tether.io/tools/indexer-api
  baseURL: https://wdk-api.tether.io
  tags:
  - Token Balances
  properties:
  - type: OpenAPI
    url: openapi/tether-token-balances-api-openapi.yml
  - type: Documentation
    url: https://docs.wdk.tether.io/tools/indexer-api
  - type: APIReference
    url: https://docs.wdk.tether.io/tools/indexer-api/api-reference
  - type: GettingStarted
    url: https://docs.wdk.tether.io/tools/indexer-api/get-started
  - type: SignUp
    url: https://wdk-api.tether.io/register
- aid: tether:tether-token-transfers-api
  name: Tether Token Transfers API
  description: Query token transfer history for addresses
  humanURL: https://docs.wdk.tether.io/tools/indexer-api
  baseURL: https://wdk-api.tether.io
  tags:
  - Token Transfers
  properties:
  - type: OpenAPI
    url: openapi/tether-token-transfers-api-openapi.yml
  - type: Documentation
    url: https://docs.wdk.tether.io/tools/indexer-api
  - type: APIReference
    url: https://docs.wdk.tether.io/tools/indexer-api/api-reference
  - type: GettingStarted
    url: https://docs.wdk.tether.io/tools/indexer-api/get-started
  - type: SignUp
    url: https://wdk-api.tether.io/register
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- url: https://tether.io/feed/
  type: BlogRSS
- type: Website
  url: https://tether.io/
- type: DeveloperPortal
  url: https://docs.wdk.tether.io/
- type: Documentation
  url: https://docs.wdk.tether.io/
- type: APIReference
  url: https://docs.wdk.tether.io/sdk/all-modules
- type: GettingStarted
  url: https://docs.wdk.tether.io/sdk/get-started
- type: Support
  url: https://docs.wdk.tether.io/overview/support
- type: Blog
  url: https://tether.io/news/
- type: GitHubOrganization
  url: https://github.com/tetherto
- type: SignUp
  url: https://wdk-api.tether.io/register
- type: TermsOfService
  url: https://tether.io/terms/
- type: PrivacyPolicy
  url: https://tether.io/privacy/
- type: Security
  url: https://tether.io/bug-bounty/
- type: OpenAPI
  url: openapi/_original/tether-wdk-indexer-openapi-original.yml
- type: Overlay
  url: overlays/tether-wdk-indexer-overlay.yaml
- type: LLMsTxt
  url: llms/tether-llms.txt
- type: Packages
  url: packages/tether-packages.yml
- type: SDKs
  url: packages/tether-packages.yml
- type: CLI
  url: cli/tether-cli.yml
- type: Components
  url: components/tether-components.yml
- type: MCPServer
  url: mcp/tether-mcp.yml
- type: ToolCrosswalk
  url: mcp/tether-tool-crosswalk.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Authentication
  url: authentication/tether-authentication.yml
- type: Conventions
  url: conventions/tether-conventions.yml
- type: RateLimits
  url: rate-limits/tether-rate-limits.yml
- type: ErrorCatalog
  url: errors/tether-problem-types.yml
- type: DataModel
  url: data-model/tether-data-model.yml
- type: Lifecycle
  url: lifecycle/tether-lifecycle.yml
- type: ChangeLog
  url: changelog/tether-changelog.yml
- type: Conformance
  url: conformance/tether-conformance.yml
- type: Sandbox
  url: sandbox/tether-sandbox.yml
- type: WellKnown
  url: well-known/tether-well-known.yml
- type: DomainSecurity
  url: security/tether-domain-security.yml
- type: VulnerabilityDisclosure
  url: security/tether-vulnerability-disclosure.yml
x-enrichment:
  date: '2026-08-05'
  status: enriched
  artifacts_added: 24
  pass: local-v1

Tether API — frequently asked questions

Does Tether have an API?

Yes. APIs.io lists 5 APIs from Tether, including Tether API Keys API, Tether Chains API and Tether Health API, and 2 more.

Is there an OpenAPI specification for the Tether API?

Yes. APIs.io indexes 5 OpenAPI specifications for Tether, each linked for download from this page.

How do I authenticate with the Tether API?

Tether uses bearer-token authentication (apiKey · 1 scheme). The details are profiled on APIs.io as Tether Authentication.

Does Tether have an MCP server?

Yes. APIs.io lists 1 MCP server for Tether: Local (stdio) MCP server; 35 tools listed.

Is the Tether API ready for AI agents?

Tether has a Kin Score of 52.1 out of 100 (developing) and an Agent Readiness score of 32.6 (agent-ready), scored by API Evangelist on 2026-11-06.

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